Why low-voltage assemblies are essential for EV charging

By Tom Mennell, General Manager of Low Voltage Distribution, Schneider Electric UK and Ireland

Big Zero Report 2023

As societies move towards their 2050 carbon-neutral goals, the adoption of electric vehicles (EVs) is becoming increasingly important. This is due to their low carbon footprint, which will help to address climate change. In fact, according to our research, 68.5% of business leaders in the UK and Ireland believe we will hit the milestone of 60% of global car sales being electric from 2030 on the road to net-zero. To make EVs the viable solution, it is integral we have the infrastructure in place so that consumers are incentivised to make the switch to electric. With this is the need to install EV chargers in vast quantities. In some instances, these will be low power chargers in domestic properties, but others will be in hubs in public places with a wide range of capacities.

Low voltage assemblies are essential to control and protect the supplies to chargers in hubs. As most charging hubs will be located in open spaces, outdoor low voltage assemblies offer significantly more benefits than indoor assemblies in small buildings or fibreglass housings. The space required is reduced, often enabling the assembly to be closer to the chargers. In addition, installation time is reduced as the assembly is delivered as a single unit, and the initial and lifetime costs are much less.

The electric vehicle charging application is more demanding than most low voltage assemblies. This is because all circuits need to be fully and continuously loaded simultaneously, and in some instances, the assembly may be managed to full load for long periods.

This article explores the specific needs of outdoor low voltage assemblies for electric vehicle charging installations.


Choosing an outdoor low voltage assembly

With the move towards a carbon-neutral society, there is considerable pressure to migrate transport away from fossil fuel to greener energy sources. Electric vehicles will play a significant role in this transition in the immediate future.

Many vehicles will ordinarily be charged at home from the domestic electricity supply. Other vehicles will be charged in hubs where charging can take place over several hours or in-service stations. A high-power fast-charging solution is essential for electric vehicles to win drivers’ confidence and replace combustion engine vehicles.

Outdoor low-voltage assemblies offer several advantages over an indoor assembly in a building. The most significant advantage is that less space is required outside, and it is easier to locate the assembly when it is closer to the point of distribution. Additionally, the installation time is significantly reduced as the assembly is usually supplied as a single complete unit; this means there is no requirement for separate buildings to be created and equipped with the basic service for charging.


Safety comes first

Charging an electric vehicle requires connection to a powerful electricity supply, even though the vehicle is situated in an outdoor environment, during a rainy period, and used by persons not aware of the risks of electricity.

Electrical safety is paramount to avoid short-circuits, overheating, or electric shocks. This is why a key consideration when installing the outdoor assemblies is that they must conform to BS 7671 and IEC 61851 industry and product standards for the electric vehicle charging equipment in both UK and Ireland. As low-voltage assemblies for electric vehicle charging supplies are often located in areas accessible to the public, additional safety features are necessary compared with other applications where access can be more restricted.

In addition, providers of charging facilities that operate over a large number of sites are increasingly appreciating the cost of downtime and loss of service to customers when charging facilities are not available. Many are now opting for fully remotely monitored services and remotely operated low voltage assemblies. These incentivise the reason for the loss of supply to be diagnosed remotely, and when it is safe to do so, supplies to be restored remotely.


Future-proofing low voltage assemblies

The anticipated life of an electrical installation and that of an electric vehicle charger are very different. This makes it vital that any low voltage assemblies forming part of the installation be very flexible, changeable and upgradeable for them to be readily adapted to match the needs of new chargers and the number of chargers, as and when they may be installed.

Looking to the future, the most likely changes to outdoor low-voltage assemblies are number and rating of circuits, manual to automated operating, local to remote monitoring and control, planned predictive maintenance. Ideally, any new low-voltage assembly that is future-proofed should be within the limits of the enclosure and be capable of being rearranged to accommodate a combination of outgoing circuit breakers. Changing the combination should take little time and be carried out without adapting the busbar and enclosure system. It should also incorporate circuit breakers with trip units that can be upgraded to enhance protection, monitoring and maintenance functions. Finally, it should include facilities that enable remote monitoring and control to be added or upgraded as applicable.

Outdoor low-voltage assemblies offer significant benefits in electricity distribution to car chargers. Of course, selecting the right design of low-voltage assembly at the time of the initial purchase can significantly reduce downtime and costs as the needs of the installation evolve – a win-win situation.

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